Spark-plug



A. R. MEYER.

SPARK PLUG.

APPLxcATmN mm 0'c1.f.\.w19.

Patented July 13, 1920.

n. ifation, like numerals of reference ALBERT B. MEYER, F SACRAMENTO, CALIFORNIA.

suini-PLUG.

Specication of Letters Eat/ent.

Patented .hay 13,1920.

Application led October 6, 1919. Serial No. 828,681.

To all whom it may concern: f

Bc it known that I, ALnnn'r R. Mnrnmn citizen of the United States, residing at Sacramento, in the county of Sacramento and State of California, have invented new and useful Improvements in Spark-Plugs, of which the following is a specification.

This invention comprchends the provision of a spark plug wherein the main electrode is insulated by glass tubing which can be quickly and easily aociated with the com' poncnt parts of the plug, or removed there from :is the occasion requires, thus elminating the use of porcelain and producin a plug which can be manufactured and sol at n nominal cost.

The nature and advantages of the invention will be better understood when the following detail description is taken in connection with the accompanying drawing, the invention residing in the construction, combination and arrangement of parts as claimed.

In the drawing forming part of this speciindicate similar parts in the several views and Wherel1 I Figure 1 a view of the plug in elevation. Fig. is u sectional view therethrough.

Fig. n detail view of the main electrode.

Fig. 4 is a view of the glass insulating indio.

Vig. 5 is :i view of the cap.

liefern-ing to the raving in detail, 10 indiv-ales ilu casingl or body ol the plug which exleriorly threaded as at 11, and interior-ly threaded at. 1Q tu accommodate'the tubular extension 13 which is detachabl associated with the .casing or body 10. e body 1U is provided with an internal shoulder 14, upon v'liich the enlargement 15 of the main electrode 16 is seated. The main electrode projects a slight distance below the casing 1() in close proximity to the electrode 18, depending from said casing. The electro-'ic adjacent its connection with the er. largement is insulated by mica which extends e short distant-.e throughout the length of the electrode. The remaining portion of the eiectrode is insulated by a glass tube 19, which surrounds the electr de and seated upon the enlargement 15. '.Ihe latter is provided withan asbestos cushion 20, aginst ars 4which 'the adjacent end of the tube 1 9 This'nend of the tube is relatively large to receive the mica 21, while the remaining portion of the tube is reduced to lit close around the electrode. The glass tube is covered with an asbestos sleeve 22 to protect the tube from the heat, and to also insulate the electrode from the'body of the lug, should fthe glass tube become broken.

he tube projects a slight distance 'above the adjacent end of the extension 13 and is received by a cap 24 slidably litted upon the electrode, the cap being lined with asbestos 25. Nuts 2G are threaded upon the electrode in the usual manner and hold the cap 24` in position.l The glass insulating tube takes the place of the porcelain now commonly employed in spark plugs, and'` not only provides a good insulator for the plug, but materially reduces the cost of manufacture and sale of such articles. The glass tubes can be readil associated with the' electrode and body of t e plug, and can also be readily separated from these parts should the occasion require. The opposite ends of the tube bear against an asbestos cushion and thus prot-ect the tube from being broken when the cap 24 and nuts 25 are arranged in op- V erative' positions.

While I have shown and described ivhat I consider the preferred embodiment of the invention, I desire to have it understood` that I do not limit myself to the exact construction and arrangement of parts dis closed, and that such changes may be resorted to when desired as `lull within the scope of what is claimed.

That is claimed is 1. A spark plug comprising a body, an internal shoulder, an electrode passed through said body, a' member seated upon said shoulder and receiving said electrode, insulating material surrounding the electrode for aportion of its length above said member, a glass tube surrounding the electrode and receiving said insulating material, said tube resting upon the said member, a cap fitted on the electrode and receiving theopposite end of said tube. means for holding the cap in position, and an electrode depending from said body.

2. A spark plug comprising a body having an internal shoulder, am electrode passed throu h said body, a member seated upon said soulder and having said electrode, insulating material surrounding said electrode abovesaid member, a glass tube surrounding said eleetrodeand receiving Said insu- Iatmg material, an asbestos sleeve covering said tube, said tube resting upon the sand member, a cup fitted upon saisi elertl'mle and receiving the opposite end of smid tube, 10 means for hoiding said sep in posLen, und an electrode depending from said body'.

In testimony whereof l affix my signature.

ALBERT R. MEYER. 

